Tuning a 4bd1

[rust]

Recently I've heard a couple of various 4BD1's tick over and most sound pretty similar. However, today I heard one that was ridiculously quiet and purred like a kitten.

Todays ex auction perentie seriously hummed in comparison to mine and the owner reckons he can easily sit on 120 on the freeway. He hasn't done anything beyond an oil change and it's just an everyday ex-army 4BD1.

What jobs would I need to do to make my 4BD1 sound and respond like that one?

[Dougal]

Idle noise is largely injection timing. But engine age also has an effect. The earlier 4BD1 engines have looser clearances and that makes them knock more. Especially when cold. Later on (particularly after the 1988 update) piston/liner clearances got tighter and the engines got much smoother and quieter.

Retarding the injection timing a little will smooth them right out at idle, but make response a little duller and can make them hard to start in the cold if you go too far.

[isuzurover]

There is not much you can do. Some sound different.

If you want to try:
Retarding the injection slightly
Increasing the idle to make it smoother
Set the tappets
Turn the fuelling up slightly

Other than that you would need to pull the engine apart to balance it.

But seriously - just fit a turbo... The turbine in the exhaust is the best means of quietenting an engine and increasing power... ;)

[walahbro]

Im with isuzurover. I've got an '88 model I've add turbo and intercooler, she runs so much quieter, less vibration at idle and so much power..you can pull up hill at 120km